Release Time:2019-03-12  Hits:

Indexed by: Journal Article

Date of Publication: 2018-10-15

Journal: OPTICS LETTERS

Included Journals: SCIE

Volume: 43

Issue: 20

Page Number: 5038-5041

ISSN: 0146-9592

Abstract: An all-optical photoacoustic spectroscopy based on lock-in white-light interferometry is proposed for trace gas detection. The cavity length of the fiber-optic Fabry-Perot cantilever microphone is demodulated by a high-speed white-light interferometer, whose spectral sampling is synchronously triggered by a phased locked signal. To improve the signal-to-noise ratio, the demodulated digital photoacoustic signal is further processed by a specially designed virtual lock-in amplifier. The designed photoacoustic spectrometer has been tested for trace acetylene (C2H2) detection in the near-infrared region. The normalized noise equivalent absorption coefficient for C2H2 is achieved to be 1.1 x 10(-9) cm(-1) W Hz(-1/2). (C) 2018 Optical Society of America